Contact-less probe of semiconductor wafers

Abstract

A device, having circuits formed thereon, comprises a circuit including a frequency generator for generating a detectable radio frequency energy when powered and a power generator, coupled to the frequency generator, for generating power when exposed to light.

Description

1. Field of the InventionThe present invention generally relates to devices for testing semiconductor wafers during manufacturing and, more specifically, to testing devices which do not contact the device under test (DUT).2. Description of the Related ArtDuring the manufacturing of semiconductor devices and wafers, unwanted defects occasionally occur. In order to reduce such defects and increase production yield it is desirable to test the item being manufactured at various points during the manufacturing process.Conventional systems remove the item being manufactured from the production line at different fabrication steps and test the item for defects. Depending on the development needs, a semiconductor wafers could be pulled at the post-silicide polysilicon stage, during the local interconnect stage or at several of the metalization stages, such as post metal-1 anneal, post via-1 planarization, or post metal-2 etch, for testing.Conventional testing systems come in physical contact...

AI Technical Summary

Benefits of technology

A radio frequency generator is one of the most versatile process and device monitors. For example, a radio frequency generator can be used to extract parameters such as device performance and silicide resistance. More specifically, the stage delay of an inverter ring oscillator designed with minimum length and narrow width MOSFETs will have a frequency which is dependent strongly on device performance and, thus, the frequency of operation can provide a measure of MOSFET performance. A second, similarly designed, inverter oscillator with very wide gates will additionally exhibit significant sensitivity to silicide resistance on the gate electrodes. Thus, a comparison of the frequency of operation of this oscillator with that of the former can afford a measure of silicide resistance.

Problems solved by technology

During the manufacturing of semiconductor devices and wafers, unwanted defects occasionally occur.

By making physical contact with the item being manufactured, the conventional systems introduce foreign materials in the production line, which increases the chance of defects being produced in subsequent processing steps and, therefore, reduces overall yield for the manufacturing process.

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